[Tom Wesenberg]

I don't use fuses, but if I did, then I'd use a 20 amp fuse right at the cutout, where the lights and horn wire connect. Then use a 30 amp fuse by the starter. Since the lights are the usual cause for a blown fuse, this way the 20 amp will blow, but the 30 amp will keep running the ignition, so you don't die in the middle of the road.